Staging: IIO: tsl2561 digital light sensor core support

This is a pretty minimalist example of an IIO driver.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jonathan Cameron 2009-08-18 18:06:21 +01:00 committed by Greg Kroah-Hartman
parent d1325cf450
commit 78632b609a
6 changed files with 309 additions and 1 deletions

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@ -12,5 +12,6 @@ menuconfig IIO
if IIO
source "drivers/staging/iio/adc/Kconfig"
source "drivers/staging/iio/light/Kconfig"
endif # IIO

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@ -5,4 +5,5 @@
obj-$(CONFIG_IIO) += industrialio.o
industrialio-y := industrialio-core.o
obj-y += adc/
obj-y += adc/
obj-y += light/

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@ -0,0 +1,13 @@
#
# Light sensors
#
comment "Light sensors"
config TSL2561
tristate "TAOS TSL2561 light-to-digital convertor"
depends on I2C
help
Say yes bere to build support for the TAOS light to digital
convertor. This chip has two light sensors. One is broadband
including infrared whilst the other measures only infrared.
Provides direct access via sysfs.

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@ -0,0 +1,5 @@
#
# Makefile for industrial I/O Light sensors
#
obj-$(CONFIG_TSL2561) += tsl2561.o

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@ -0,0 +1,12 @@
#include "../sysfs.h"
/* Light to digital sensor attributes */
#define IIO_DEV_ATTR_LIGHT_INFRARED(_num, _show, _addr) \
IIO_DEVICE_ATTR(light_infrared##_num, S_IRUGO, _show, NULL, _addr)
#define IIO_DEV_ATTR_LIGHT_BROAD(_num, _show, _addr) \
IIO_DEVICE_ATTR(light_broadspectrum##_num, S_IRUGO, _show, NULL, _addr)
#define IIO_DEV_ATTR_LIGHT_VISIBLE(_num, _show, _addr) \
IIO_DEVICE_ATTR(light_visible##_num, S_IRUGO, _show, NULL, _addr)

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@ -0,0 +1,276 @@
/*
* tsl2561.c - Linux kernel modules for light to digital convertor
*
* Copyright (C) 2008-2009 Jonathan Cameron <jic23@cam.ac.uk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Some portions based upon the tsl2550 driver.
*
* This driver could probably be adapted easily to talk to the tsl2560 (smbus)
*
* Needs some work to support the events this can generate.
* Todo: Implement interrupt handling. Currently a hardware bug means
* this isn't available on my test board.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include "../iio.h"
#include "../sysfs.h"
#include "light.h"
#define TSL2561_CONTROL_REGISTER 0x00
#define TSL2561_TIMING_REGISTER 0x01
#define TSL2561_THRESHLOW_LOW_REGISTER 0x02
#define TSL2561_THRESHLOW_HIGH_REGISTER 0x03
#define TSL2561_THRESHHIGH_LOW_REGISTER 0x04
#define TSL2561_THRESHHIGH_HIGH_REGISTER 0x05
#define TSL2561_INT_CONTROL_REGISTER 0x06
#define TSL2561_INT_REG_INT_OFF 0x00
#define TSL2561_INT_REG_INT_LEVEL 0x08
#define TSL2561_INT_REG_INT_SMBUS 0x10
#define TSL2561_INT_REG_INT_TEST 0x18
#define TSL2561_ID_REGISTER 0x0A
#define TSL2561_DATA_0_LOW 0x0C
#define TSL2561_DATA_1_LOW 0x0E
/* Control Register Values */
#define TSL2561_CONT_REG_PWR_ON 0x03
#define TSL2561_CONT_REG_PWR_OFF 0x00
/**
* struct tsl2561_state - device specific state
* @indio_dev: the industrialio I/O info structure
* @client: i2c client
* @command_buf: single command buffer used for all operations
* @command_buf_lock: ensure unique access to command_buf
*/
struct tsl2561_state {
struct iio_dev *indio_dev;
struct i2c_client *client;
struct tsl2561_command *command_buf;
struct mutex command_buf_lock;
};
/**
* struct tsl2561_command - command byte for smbus
* @address: register address
* @block: is this a block r/w
* @word: is this a word r/w
* @clear: set to 1 to clear pending interrupt
* @cmd: select the command register - always 1.
*/
struct tsl2561_command {
unsigned int address:4;
unsigned int block:1;
unsigned int word:1;
unsigned int clear:1;
unsigned int cmd:1;
};
static inline void tsl2561_init_command_buf(struct tsl2561_command *buf)
{
buf->address = 0;
buf->block = 0;
buf->word = 0;
buf->clear = 0;
buf->cmd = 1;
}
static ssize_t tsl2561_read_val(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret = 0, data;
ssize_t len = 0;
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct tsl2561_state *st = indio_dev->dev_data;
mutex_lock(&st->command_buf_lock);
st->command_buf->cmd = 1;
st->command_buf->word = 1;
st->command_buf->address = this_attr->address;
data = i2c_smbus_read_word_data(st->client, *(char *)(st->command_buf));
if (data < 0) {
ret = data;
goto error_ret;
}
len = sprintf(buf, "%u\n", data);
error_ret:
mutex_unlock(&st->command_buf_lock);
return ret ? ret : len;
}
static IIO_DEV_ATTR_LIGHT_INFRARED(0, tsl2561_read_val, TSL2561_DATA_0_LOW);
static IIO_DEV_ATTR_LIGHT_BROAD(0, tsl2561_read_val, TSL2561_DATA_1_LOW);
static struct attribute *tsl2561_attributes[] = {
&iio_dev_attr_light_infrared0.dev_attr.attr,
&iio_dev_attr_light_broadspectrum0.dev_attr.attr,
NULL,
};
static const struct attribute_group tsl2561_attribute_group = {
.attrs = tsl2561_attributes,
};
static int tsl2561_initialize(struct tsl2561_state *st)
{
int err;
mutex_lock(&st->command_buf_lock);
st->command_buf->word = 0;
st->command_buf->block = 0;
st->command_buf->address = TSL2561_CONTROL_REGISTER;
err = i2c_smbus_write_byte_data(st->client, *(char *)(st->command_buf),
TSL2561_CONT_REG_PWR_ON);
if (err)
goto error_ret;
st->command_buf->address = TSL2561_INT_CONTROL_REGISTER;
err = i2c_smbus_write_byte_data(st->client, *(char *)(st->command_buf),
TSL2561_INT_REG_INT_TEST);
error_ret:
mutex_unlock(&st->command_buf_lock);
return err;
}
static int tsl2561_powerdown(struct i2c_client *client)
{
int err;
struct tsl2561_command Command = {
.cmd = 1,
.clear = 0,
.word = 0,
.block = 0,
.address = TSL2561_CONTROL_REGISTER,
};
err = i2c_smbus_write_byte_data(client, *(char *)(&Command),
TSL2561_CONT_REG_PWR_OFF);
return (err < 0) ? err : 0;
}
static int __devinit tsl2561_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret = 0, regdone = 0;
struct tsl2561_state *st = kzalloc(sizeof(*st), GFP_KERNEL);
if (st == NULL) {
ret = -ENOMEM;
goto error_ret;
}
i2c_set_clientdata(client, st);
st->client = client;
mutex_init(&st->command_buf_lock);
st->command_buf = kmalloc(sizeof(*st->command_buf), GFP_KERNEL);
if (st->command_buf == NULL) {
ret = -ENOMEM;
goto error_free_state;
}
tsl2561_init_command_buf(st->command_buf);
st->indio_dev = iio_allocate_device();
if (st->indio_dev == NULL) {
ret = -ENOMEM;
goto error_free_command_buf;
}
st->indio_dev->attrs = &tsl2561_attribute_group;
st->indio_dev->dev.parent = &client->dev;
st->indio_dev->dev_data = (void *)(st);
st->indio_dev->driver_module = THIS_MODULE;
st->indio_dev->modes = INDIO_DIRECT_MODE;
ret = iio_device_register(st->indio_dev);
if (ret)
goto error_free_iiodev;
regdone = 1;
/* Intialize the chip */
ret = tsl2561_initialize(st);
if (ret)
goto error_unregister_iiodev;
return 0;
error_unregister_iiodev:
error_free_iiodev:
if (regdone)
iio_device_unregister(st->indio_dev);
else
iio_free_device(st->indio_dev);
error_free_command_buf:
kfree(st->command_buf);
error_free_state:
kfree(st);
error_ret:
return ret;
}
static int __devexit tsl2561_remove(struct i2c_client *client)
{
struct tsl2561_state *st = i2c_get_clientdata(client);
iio_device_unregister(st->indio_dev);
kfree(st);
return tsl2561_powerdown(client);
}
static unsigned short normal_i2c[] = { 0x29, 0x39, 0x49, I2C_CLIENT_END };
I2C_CLIENT_INSMOD;
static const struct i2c_device_id tsl2561_id[] = {
{ "tsl2561", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tsl2561_id);
static struct i2c_driver tsl2561_driver = {
.driver = {
.name = "tsl2561",
},
.probe = tsl2561_probe,
.remove = __devexit_p(tsl2561_remove),
.id_table = tsl2561_id,
};
static __init int tsl2561_init(void)
{
return i2c_add_driver(&tsl2561_driver);
}
module_init(tsl2561_init);
static __exit void tsl2561_exit(void)
{
i2c_del_driver(&tsl2561_driver);
}
module_exit(tsl2561_exit);
MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
MODULE_DESCRIPTION("TSL2561 light sensor driver");
MODULE_LICENSE("GPL");